I prefer to walk, I find that walking tends to keep me more focused on my game. Not that I don't help partners find balls, but a lot of the time when walking, all I have to do is focus on my ball, my swing, my game. I also find that I stay more at ease with my game, I don't feel like I'm rushing to the ball and have to hurry up and hit it and then rush to my partners ball and so on. As I approach my ball, I'm getting myself ready for the shot, running all of the conditions through my head, distance, wind conditions, obstacles and so on. When I get to my ball, all I really need to see is the lie, then I pull a club and I'm ready to swing.
I actually joined a course 25 miles from my house because it is walkable, a lot of the courses in my area you just can't walk. Either too hilly or just not set up for walkers. The course I joined is an old school course, built in the late 1930's, and made for walking. It's not a long course, about 6200 yards from the tips, but very playable and challenging. This weekend, my brother and I played in 3 hours, even with a 20mph wind with gust to 35.